Target description
This tutorial helps to:
- Use the X-NUCLEO-SNK1M1 shield that includes a TCPP01-M12 protection circuit and provides a USB Type-C® connector
- Create a USB-PD Sink device with the NUCLEO-G071RB board and the X-NUCLEO-SNK1M1 using STM32CubeMX software
Prerequisites
- Computer with Windows 7 (or higher)
- Computer with Windows 7 (or higher)
Hardware
Software
Literature
- UM2324 NUCLEO-G071RB User Manual
- UM2773 X-NUCLEO-SNK1M1 User Manual
How to build an USBPD Sink application using the X-Cube-TCPP software pack
Create a USB-PD Sink Device
Total 45min
1. Software pack installation
Open STM32CubeMX, in the software pack area, click on the install/remove button.
Then select the STMicroelectronics tab, scroll down to the X-Cube-TCPP software pack, and click on the install button if it is not already installed.
2. Creating the project
5min
In STM32CubeMX, create a new STM32 project. As a target selection, choose the NUCLEO-G071RB from the Board Selector Tab.
Click "Start Project", then in the file menu, create a new folder under your project's name, and click "Save".
When prompted for initializing peripherals with their default mode, click No.
3. Configuring the system
At this point, your project is created. The next steps show how to configure the peripherals and options needed for the project.
3.1. Clear the pinout
To start from a blank configuration, click on the Pinout menu and select Clear Pinouts. This will reset the pinouts in the Pinout view.
3.2. Select the X-CUBE-TCPP software pack
From the software pack menu:
Select the X-CUBE-TCPP Software pack and enable its Sink application, the tcpp01 board part, and the X-NUCLEO-SNK1M1 board support.
3.3. Configure UCPD peripheral
In the Connectivity tab, select the UCPD1 peripheral and enable it in sink mode. Under the NVIC Settings tab, enable UCPD global interrupts.
Under the DMA Settings tab, add UCPD1_RX and UCPD1_TX DMA requests. Select DMA1 channel 4 for RX and DMA1 channel 2 for TX.
3.4. Configure FreeRTOS Middleware
In the Middleware section, enable FreeRTOS with CMSIS_V1 interface. Under the Config Parameters tab, change "TOTAL_HEAP_SIZE" to 7000 bytes.
3.5. Configure USBPD Middleware
In the Middleware section, enable USBPD with the following configuration:
- Port configuration: Port 0: UCPD1
- Stack configuration: PD3 Full Stack
- Timer service source: TIM1
Under the PDO Sink tab is the PDO description
- Number of Sink PDOs for port 0: 1
- Port 0 Sink PDO 0 is 5V
3.6. Configure ADC peripheral
For the Power Delivery stack to work, VBUS needs to be monitored. To do it, an ADC needs to be configured to measure the VBUS voltage and current.
As the X-NUCLEO-SNK1M1 BSP is used here, the ADC configuration is not needed in CubeMX.
As the ADC HAL drivers are needed for it to work properly, it is still necessary to configure the ADC in CubeMX for it to include the driver files, but the actual configuration and init function are not called in this project.
In the Analog section, enable ADC1 peripheral channel 0. Leave the configuration as default, as the software pack reconfigures it.
3.7. Enable the software pack
In the middleware and software pack category, select the X-CUBE-TCPP software pack. Enable the 'Source' application, the 'tcpp01' board part, and the 'X-NUCLEO-SNK1M1' board support.
3.8. Configure the clocks
Under the Clock Configuration main tab, change the system clock mux to PLLCLK. It sets the HCLK clock to 64 MHz.
3.9. [OPTIONAL] Configure Tracer for debug
3.9.1. Configure LPUART
On the STM32G0 Nucleo-64 board, the Virtual COM port connected to the ST-LINK is the LPUART1.
In the Connectivity section, enable LPUART1 in asynchronous mode, and baud rate to 921600 bauds. Leave the rest as default.
In the pinout view, left-click PA2 and PA3 to remap them to LPUART1_TX and LPUART1_RX.
Under the DMA Configuration tab, add a request for LPUART1_TX. Use DMA1 channel 3.
Finally, under the NVIC Settings tab, enable LPUART1 global interrupts.
3.9.2. Configure embedded tracer
In the Utilities section, select TRACER_EMB and use LPUART1 as the trace source.
Then, go back to the USBPD middleware configuration and check the Tracer Source checkbox.
3.9.3. Configure UCPD monitor firmware responder for debug
The firmware interactive stack responder can be activated if interaction with the USB-PD stack is needed, using the UCPD monitor tool. STM32CubeMonUCPD. GUI can be activated only with tracer. In the "Utilities" section, enable GUI_INTERFACE, then enter free text to describe the board.
4. Configure the project
5min
Under the Project Manager main tab, configure the minimum stack size to 0xC00 under the Project tab. This is a first value, which can be tuned later, depending on application needs.
For STM32G0 or G4 MCU, uncheck “Use default firmware location” and instead, select the Software pack “c:|\user\ … \STM32Cube\Repositoryctronics/Packs\STMicroelectronics\X-CUBE-TCPP\V4.1.0\” as the firmware location to be sure to use the latest USBPD lib releases, as the standard evolution is very fast.
Under the Advanced Settings tab, change the LPUART driver to LL to save a bit of memory heap size. As ADC initialization functions are not needed (handled by the BSP drivers), uncheck Generate Code for the MX_ADC1_Init functions.
5. Generate the code
Save your file with Ctrl+s and select generate code.
A warning appears, informing that a proper HAL time base is not defined. It is safer to use a dedicated timer as a HAL time base source.
For this demonstration, the below warning can be ignored by clicking Yes.
6. Configure the shield's jumpers
Place jumpers on the X-NUCLEO-SNK1M1 shield as shown in the picture.
7. Compile and run the application
The compilation must be performed without error or warnings.
Build the application by clicking on the button (or select Project/Build Project).
Run the application by clicking on the button (or select Run/Run).
8. Establish the first explicit contract
5min
With your application running on the board, launch the STM32CubeMonitor-UCPD application.
The user's board must appear in the list when clicking "Refresh list of connected boards". Double click on the
corresponding line (or click "NEXT").
Note: The ComPort may be different. It depends on the number of boards installed on the computer. Double click on the desired UCPD port, here Port 0, or select it and click "NEXT".
Click on the TRACES button in the bottom right corner to get protocol traces. You can then plug a power delivery source into the USB Type-C® receptacle of the X-NUCLEO-SKN1M1 shield. The screen may look like this:
The figure above shows the communication between the STM32G0 and the power delivery source on the right panel. It is possible to verify the correct sequence to reach an explicit contract:
- The capabilities are sent by the source (IN green message).
- The request is sent by the STM32G0 (OUT orange message).
- The ACCEPT and the PS_RDY are sent by the source (IN green message).
- The contract negotiation ends by the POWER_EXPLICIT_CONTRACT notification (blue message).
For more details on how to use this tool, refer to UM2468. And for more details on the protocol, refer to UM2552. Note that this trace is very helpful for debugging and application development.
9. Information focus : Code inserted by the software pack
By enabling the software pack in section 3.7, the code below has been added automatically in the following files:
Expandusbpd_dpm_user_h |
Expandusbpd_dpm_user_c |
Expandusbpd_pdo_defs.h |
Expandusbpd_pwr_if.c |
Expandusbpd_pwr_user.c |
You can find other applicative examples on GitHub: x-cube-tcpp
10. Project with a custom board
This chapter allows building an USBPD source application using a custom board with an STM32 MCU from series G0, G4, H5, L5, or U5 that includes the UCPD peripheral.
- As in chapter 2: Create the project
- As in chapter 3.1: Clear the pinout
- As in chapter 3.2: Select the X-CUBE-TCPP software pack
Do not select the board support for X-NUCLEO-SNK1M1, as your application is based on a custom board.
- As in chapter 3.3: Configure UCPD Peripheral
- As in chapter 3.4: Configure FreeRTOS Middleware
- As in chapter 3.5: Configure USBPD Middleware
- Configure ADC Peripheral
Select and configure the ADC and its channel on which Vbus is connected for monitoring. Select the ADC and its channel. Adjust the clock prescaler. Keep 12 Bits resolution. Enable the continuous conversion mode, and set a medium cycle sampling time.
- Configure GPIO
In the Pinout view, select the GPIO output for TCPP01 VCC and a second GPIO output for TCPP01 DB.
- Enable the software pack
In the middleware category, select the X-CUBE-TCPP software pack and enable its application and board part.
- Assign resources to the application requirements
- As in chapter 4: Configure the project
However, in the Advanced settings, keep ADC initialization code generation.
- As in chapter 5: Generate code
- As in chapter 7: Compile and run the application
11. References